Aerosol valve for low delivery rate

ABSTRACT

A low delivery rate aerosol valve comprising a valve body extension having at least one additional restricted orifice to provide a plurality of restricted orifices disposed in series relative to each other and the valve body cavity such that product passes through the restricted orifices in succession and from there to the valve body cavity and valve stem discharge orifice and through the terminal orifice.

United States Patent 1 1 Conway et al.

[ Dec. 17,1974

[731 Assignee'. S.'C. Johnson & Son, Inc., Racine,

Wi's.

[221 Filed: Jan. 15, 1973 [21] Appl. No.: 323,679

Us. or.

[52] 222/402.24 [51] Int. Cl B65 d 83/14 [58] Field of SearchZZZ/402.24, 564, 382, 464,

222/547; 138/44, 26; 60/271; 417/557; 285/177, DIG. 22; 239/344, 337

A low'delivery rate aerosol valve comprising a valve [56] ReferencesCited UNITED STATES PATENTS 1,740,471 12/1929 McBride 239/344 1,947,9092/1934 Hollander 138/44 2,855,753 10/1958 McLafferty... 60/271 UX3,085,753 4/1963 Brau n et al. 285/D1G. 22 3,297,256 1/1967 Hickerson etal. 60/271 X 3,412,937

Primary Examiner-Stanley H. Tollberg Assistant Examiner -NormanLStaclclr.

ABSTRACT body extension having at 'least one additional restrictedorifice to provide a plurality of restricted orifices disposed in seriesrelative to each other-and the valve body cavity such that productpassesthrough the restricted orifices in succession and from there to thevalve body cavity and valve stem discharge orifice and through theterminal orifice.

7 Claims, 5 Drawing Figures Chamberlain 239/344 X 1. Field of theInvention This invention relates generally to aerosol valves and, inparticular, to aerosol valves designed to deliver a fluid product at areduced rate.

2. Description of the Prior Art Aerosol dispensers usually consist of acontainer under superatmospheric pressure with a valve at the upper endthereof to control discharge of the product.

The valve is generally manually operable and of the type which is biasedto seal the discharge opening when the aerosol container is not in use.Adip tube is generally provided which extends downwardly into a liquidproduct to a point adjacent to the container bottom.

In such aerosol dispensers, a gaseous propellant normally occupies thespace in the container at the top, around the valve. This space iscommonly referred to in the trade as the head space. In the usual case,liquid product and liquid propellant are located beneath the head space.As the head space increases with use, the liquid propellant'vaporizes,keeping the overall inside container pressure and thus the flow rate ofproduct up the dip tube relatively constant. In some cases, compressedgases such as N O, CO and N are used as propellant. These will bediscussed later in this application.

Several methods have been used to obtain a slow discharge rate inaerosol dispensers of thetype described above. One method has been touse a capillary dip tub, that is, a dip tube with a very small innerdiameter. This effectively slows the'discharge rate of the liquidproduct. Another idea which has been used to slow the discharge rate hasbeen to reduce the diameter of the discharge orifice. A third way hasbeen to use a vapor tap, that is,'to intentionally create a leak fromthe head space into the discharge stream in order to reduce the pressuredrop across a valve body orifice thereby reducing the flow of liquidinto the valve body and out the terminal orifice.

Each of these ideas for obtaining a low delivery rate in an aerosolvalve has disadvantages in certain situations. In particular,difficulties arise when the fluid product to be dispensed has a highsolids content, when the aerosol package will undergo misuse (that is,occasional use in positions other than an upright position), and/or whena particular type of discharge stream, namely a spray composedofrelatively large particles, is desired.

In the case of a capillary dip tube, especially a flexi-- ble plasticcapillary dip tube, it is very difficult to maintain proper orientationwithin the container. Because of the unreliable orientation of the diptube, misuse may frequently occur. Misuse, of course, occurs any timethe lower open end of the diptube is exposed to vapor rather than to theproduct to be dispensed. Further, when the container is being misused,because of the limited dip tube capacity in a capillary dip tube, itwould take only a brief period of time to exhaust the liquid contents ofthe dip tube before, the misuse would become damaging, that is, beforevapor would be exhausted from the container.

In the case of reducing the diameter in the discharge orifice as amethod of obtaining a low flow rate valve, clogging can readily occurespecially if such a valve is used with a product having a high solidscontent. Further, the use of such small reduced diameter orifices canresult in large discharge rate fluctuations because proportionally largevariations in cross-sectional area result from variations in the orificediameter which are within normal production tolerances. Furthermore,there is a practical lower limit in the diameter of an orifice. Theseproblems make the use of drastically reduced orifices undesirable orimpossible in many situations.

A third known way of reducing the flow rate, namely the use of a vaportap, may be out of the question when a product is to be dispensed in aspray having particles (or droplets) of a large size. The addition ofthe vapor in the product stream may have a tendency to agitate and breakup the fluid product into small particles thus defeating the possibilityof the desired large particles in the spray.

The valve of this invention overcomes all of these problems by providinga low delivery rate while at the same time avoiding the problems ofmisuse, clogging, 7

types of products. When using compressed gases, such' as N 0, CO and Nthe pressure decreases as the head space increases during product usage.Thus, to have a high enough pressure level when the product is nearlydepleted, it is necessary to have a very high pressure initially, thatis, when the head space is quitesmall. With such a high pressure andsuch changes in pressure, a low delivery rate is needed to avoid radicalchanges in spray characteristics. The valve of this invention is asuperior way to achieve a low flow rate in high pressure aerosolproducts which use compressed gases as propellants.

The low delivery rate valve of this invention is characterized by anupstream valve body extension having at least one additional restrictiveorifice to provide a plurality of restricted orifices within the valvedisposed in series relative to each other and to the valve body cavitysuch that product passes through the restricted orifices in successionand from thereto the valve body cavity, the valve stem discharge orificeand the terminal orifice. This valve is a superior device for obtaininga low delivery rate from an aerosol container. The problems of capillarydip tubes, extremely small orifices and vapor taps may be avoided Diptubes having significant product capacity may be used, thusprovidingenough product in the dip tube that product will 7 continue tobe expelled for a period of time during which a container is beingmisused. The plurality of restricting orifices may each be of sizesufficient to An object of this invention is to provide an aerosol valveovercoming the aforementioned problems.

Another object of this invention is to provide a low delivery rate valveovercoming the problems associated with capillary dip tubes, vapor taps,and extremely small orifices. I

Another object of this invention is to provide a valve for low deliveryrate which may be used in a product undergoing some misuse withoutsustaining the detriment associated with misuse when a small capacitydip tube, such as a capillary dip tube, is used.

Yet another object of this invention is to provide a low delivery ratevalve which is not prone to clogging even with products having a highsolids content.

Another object of this invention is to provide a low delivery rate valvethe delivery rate of which may be readily varied by the use of piggybackvalve extension members. I

A still further object of this invention is to provide a low deliveryrate valve which will allow a large particle spray.

Another object of this invention is to provide a low delivery rate valvewhich has superior functional characteristics when used in an aerosolproduct having a compressed gas propellant. I

These and other important objects will become apparent from thefollowing description and from the drawings showing preferredembodiments wherein:

FIG. 1 is a cross-sectional side view of one embodiment of thisinvention.

FIG. 2 is a cross-sectional side view of an alternative embodiment.

FIG. 3 is a cross-sectional side view of a third embodiment.

FIG. 4 is a cross-sectional side view of a fourth embodiment. FIG. 5 isa fragmentary cross-sectional sideview of a fifth embodiment of thisinvention.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS In FIG. 1, a typical aerosoldispenser upon which the invention may be used is illustrated,consisting of a container having a mounting cup 12 attached thereto.

As also shown in FIG. 1, the device of the present invention comprises avalve generally indicated as 14. Valve 14 is contained within thecustomary central turret portion of the mounting cup 12 with a tubularvalve stem 18 protruding through the central aperture 20 of mounting cup12. Valve stem 18, including discharge orifice 22, is movably arrangedwithin cavity 24 and spring biased in the sealed or closed position byvalve spring 26. Spring 26 is compressed between the enlarged lowerportion 27 of valve stem 18 and a shelf 28 in the interior of the valvebody 29. A valve button 30, including terminal orifice 32, is affixed tothe upper portion of the stem 18 protruding upwardly out of thecontainer. Sealing means 16, a rubber ring, provides sealing engagementbetween the top of valve body 29 and the inside of mounting cup 12.Valve body 29 has an uppermost annular enlargement snap fitted beyondannular head 23.

'Valve body 29, which is substantially circular in any section cutnormal to its axis, comprises an enlarged upper portion 34 which definescavity 24. Extending downwardly from upper portion 34. is a lowerportion 36 terminating in a restricted feed orifice 38. Affixed grooveand ring could be reversed. Extension 40 maybe secured to valve body 16in a variety of other ways. In some cases, extension 40 may beintegrally formed withthe valve body 29.

As shown in FIG. 2, the extension may comprise a dip tube 50 affixed tothe lower portion 36 of ,valve body 29. Extension 40 defines arestrictive'feed orifice 44 at its lower end, and dip tube 50 definesexpansion chamber 42.

FIG. 3 shows another alternative embodiment of the present invention.'Valve body extension 40 is connected to the reduced diameter lowerportion 36 of valve body 29, which terminates in valve body restrictedfeed orifice 38. Valve body extension 40 defines a plurality ofexpansion chambers 52 set apart by a plurality of restricted feedorifices 54. Extension 40 may be secured to valve body 16 in a varietyof other ways. In some cases, extension 40 may be integrally formed withthe valve body 16,

As shown in FIG. 2, the extension may comprise a dip tube 50 affixed tothe lower portion 36 of valve body 29. Extension 40 defines arestrictive feed orifice 44 at its lower end, and dip tube 50 definesexpansion chamber 42.

FIG. 3 shows another alternative embodiment of the present invention.Valve body extension 40 is connected to the reduced diameter lowerportion 36 of valve body 29, which terminates in valve body restrictedfeed orifice 38. Valve body extension 40 defines a plurality ofexpansion chambers 52 set apart by a plurality of restricted feedorifices 54. Extension 40 may be formed in a dip tube or may be aseparate piece formed by molding or otherwise. If extension. 40 is aseparate piece, a dip tube may be attached to extension 40 and extenddownwardly into the liquid contents of a container. Alternatively, thedip tube could be connected to the upper portion 56 of extension 40,which has a larger diameter and a larger capacity.

FIG. 4 shows still another embodiment comprising valve body 29, dip tube50 and a plug 58 defining restricted feed orifice 60. Plug 58 may beforce fitted into dip tube 50 or include an annular locking groove 62which engages a corresponding ring 64 formed on the interior of the diptube 50. Plug 58 may be placed at any desired location along thelengthof dip tube 50.

FIG. 5 shows another embodiment of this invention illustrating how aplurality of extension members 66, which are similar to valve bodyextension 40 shown in FIG. 1, may be piggy-backed to further restrictthe flow rate within a valve. For each additional extension member 66,the valve has an additional restricted orifice and an additionalexpansion chamber. The dip tube 50 is attached to the extension memberfurthest upstream. Because of the variations possible in the number ofextension members 66 andin the orifice sizes of such members a valvingsystem which may be easily adjusted to obtain a desired low deliveryrate is provided.

The valve body extensions of this invention are preferably made ofplastic materials. The dip tubes which form the valve body extensionsare preferably of flexible plastics while the extension shown in FIG. 1and the extension members shown in FIGS. 3 and 5 are preferably formedof hard plastic materials. There are several methods presently knownwhich may be used in forming valve body extensions.

With reference to FIG. 1, in operation, product is dispensed bydepressing button actuator 30. As button actuator 30 is depressed,discharge orifice 22 is exposed to the interior of valve body cavity 24,having been axially displaced below seal 16. This allows product to flowfrom the interior of the container through restricted feed orifice 44into expansion chamber 42 and from there through valve body restrictedfeed orifice 38 and into valve body cavity 24. The product flows fromvalve body cavity 24 through discharge orifice 22- into dischargepassage 19 defined in valve stem 18 and out the terminal orifice 32.

In the alternative embodiment of FIG. 2, product flows throughrestricted feed orifice 44, expansion chamber 42, restricted feedorifice 38 and into valve body cavity 24. The product is then dispensedin the manner previously described.

The low delivery rate valve of this invention, which has been describedin detail, overcomes the problemsassociated with previously known lowdelivery rate valves. A precise low delivery rate may be obtained.Further, such a delivery rate may be obtained without problems ofclogging, without a breakdown in particle size when large sprayparticles are desired, and without suffering the disadvantages normallyaccompanying occasional misuse of a pressurized container. It. isfurther believed that there is an additional advantage relating to a lowflow rate valve in a product in which large spray particles are desired.In such cases, when a vaporizing liquid propellant is used, it isbelieved that the upstream expansion chambers provided in this inventionhave the beneficial effect of allowing additional amounts of liquidpropellant to be removed from a liquid state to a gaseous state prior toexpulsion of the product from the terminal orifice. Thus, the liquidbeing expelled from the terminal orifice contains a smaller amount ofliquid propellant, thereby reducing the expansion which breaks suchproduct into minute particles. Theoretically, in some cases, it would bepossible to remove nearly all of the liquid propellant from the liquidproduct prior to its passage through the terminal orifice. This wouldprevent explosions of droplets as they exit the terminal orifice andtend to promote large particle size in the spray.

While in the foregoing specification, this invention has been describedin relation to certain preferred em- .bodiments, and many details havebeen set forth for purpose of illustration, it will be apparent to thoseskilled in the art that the invention is s'useptible to additionalembodiments and that certain of the details described herein can bevaried considerably without departing from the basic principles of theinvention.

We claim:

1. A low delivery rate aerosol valve comprising a valve body including avalve body cavity and a valve body restricted feed orifice, a valve stemincluding at least one inlet orifice and a discharge passage, said valvestem movably mounted within said valve body cavity, a spray nozzledefining a terminal orifice in fluid communication with said valve stem,a biasing means to normally bias said valve stem to the closed position,and a valve body extension defining a plurality of expansion chambers,each of said expansion chambers interconnected to its adjacent expansionchamber by a restricted feed orifice, said expansion chamberscommunicating in series with the interior of said valve body cavitythrough said valve body restricted feed orifice such that upon actuationof the valve the contents of the dispenser pass in series through therestricted feed orifices and expansion chambers of said valve bodyextension, said valve body restricted feed orifice, said valve bodycavity, said inlet orifice and discharge passage of said stem and saidterminal orifice to the atmosphere, whereby the contents of thedispenser are delivered at a low rate.

2. In an aerosol valve of the type having a valve body defining a valvecavity and a restricted valve body orifice through which product enterssaid cavity from an associated container, a valve stem movably mountedwithin said cavity and defining an inlet orifice and a dischargepassage, a spray nozzle attached to and in fluid communication with saidstem and defining a terminal spray orifice, and means to bias said stemto a closed position, the improvement of additional means defining atleast one expansion chamber positioned below said valve cavity and belowsaid restricted valve body orifice, said additional means defining asecond restricted feed orifice for product entry to said expansionchamber, whereby product is delivered by said valve at a reduced flowrate.

3. The valve of claim 2 wherein said valve body includes a valve bodytail which defines said valve body restricted feed orifice, and saidadditional means comprising an extension member coupled to said tailsuch that said expansion chamber is adjacent said tail, said extensionmember further defining said second restricted feed orifice remote fromsaid tail.

4. The valve of claim 2 wherein said additional means comprises anelongate dip tube attached to said valve body and having said secondrestricted feed orifice remote from said valve body.

5. The valve of claim 4 wherein said restrictedfeed orifice remote fromsaid valve body-is defined bya plug in said clip tube. v I I 6. Thevalve of claim 2 wherein said additional means comprises at least oneextension member which may be removably attached to said valve body.

7. The valve of claim 6 wherein said at least one extension membercomprises a plurality of extension members removably attached togetherin piggy-bac fashion.

1. A low delivery rate aerosol valve comprising a valve body including avalve body cavity and a valve body restricted feed orifice, a valve stemincluding at least one inlet orifice and a discharge passage, said valvestem movably mounted within said valve body cavity, a spray nozzledefining a terminal orifice in fluid communication with said valve stem,a biasing means to normally bias said valve stem to the closed position,and a valve body extension defining a plurality of expansion chambers,each of said expansion chambers interconnected to its adjacent expansionchamber by a restricted feed orifice, said expansion chamberscommunicating in series with the interior of said valve body cavitythrough said valve body restricted feed orifice such that upon actuationof the valve the contents of the dispenser pass in series through therestricted feed orifices and expansion chambers of said valve bodyextension, said valve body restricted feed orifice, said valve bodycavity, said inlet orifice and discharge passage of said stem and saidterminal orifice to the atmosphere, whereby the contents of thedispenser are delivered at a low rate.
 1. A low delivery rate aerosolvalve comprising a valve body including a valve body cavity and a valvebody restricted feed orifice, a valve stem including at least one inletorifice and a discharge passage, said valve stem movably mounted withinsaid valve body cavity, a spray nozzle defining a terminal orifice influid communication with said valve stem, a biasing means to normallybias said valve stem to the closed position, and a valve body extensiondefining a plurality of expansion chambers, each of said expansionchambers interconnected to its adjacent expansion chamber by arestricted feed orifice, said expansion chambers communicating in serieswith the interior of said valve body cavity through said valve bodyrestricted feed orifice such that upon actuation of the valve thecontents of the dispenser pass in series through the restricted feedorifices and expansion chambers of said valve body extension, said valvebody restricted feed orifice, said valve body cavity, said inlet orificeand discharge passage of said stem and said terminal orifice to theatmosphere, whereby the contents of the dispenser are delivered at a lowrate.
 3. The valve of claim 2 wherein said valve body includes a valvebody tail which defines said valve body restricted feed orifice, andsaid additional means comprising an extension member coupled to saidtail such that said expansion chamber is adjacent said tail, saiDextension member further defining said second restricted feed orificeremote from said tail.
 4. The valve of claim 2 wherein said additionalmeans comprises an elongate dip tube attached to said valve body andhaving said second restricted feed orifice remote from said valve body.5. The valve of claim 4 wherein said restricted feed orifice remote fromsaid valve body is defined by a plug in said dip tube.
 6. The valve ofclaim 2 wherein said additional means comprises at least one extensionmember which may be removably attached to said valve body.
 7. The valveof claim 6 wherein said at least one extension member comprises aplurality of extension members removably attached together in piggy-backfashion.